A variety of optical devices include an active component such as a light sensor or modulator. These active components typically guide a light signal through a component waveguide while an electrical field is applied to the component waveguide. The component waveguide can be partially defined by a ridge that extends upwards from slab regions. The performance of these components can be adversely affected by the presence of stray light signals from other components being present in the slab regions. Additionally or alternately, these components can be adversely affected when thermal energy from other components on the device travels through the device to the component. As a result, there is often a need to thermally, electrically, and/or optically isolate these components from other components on the same device.